Color-matching paint is an important step in the automobile repair process. It is also one of the most variable steps in the repair process. Typically, automobiles are assigned a paint color code by the manufacturer. This paint color code is often used by the paint formulator to generate an initial or starting point paint formulation. Starting point paint formulations can also be identified using spectrophotometric or “paint variance” techniques.
The “paint variance” method of matching paints is based on the measurement of color variability on actual vehicles. Vehicle colors can vary within an assembly plant or from plant to plant due to different paint chemistries. Some paint manufacturers survey vehicles from the different assembly plants and, based on the surveys, measure the variability of the color. Using this information, the paint manufacturer determines the variances in their formulation in order to best match the paint of a specific vehicle. A formulation deck contains the primary formula and variance formulations applied on a card. The formulation decks are typically updated about every six months and distributed to the painters under a fee-based service contract.
Often times, however, the formulation that the painter mixes based on the formulation deck recommendation does not provide an acceptable match. At this point, the painter needs to rely on his skills to match the vehicle paint by color-matching the paint formulation. Some paint manufacturers provide crude tinting guides, but these guides require the painter to apply complex color science information and relate it to a specific batch of paint using an abstract thought process. These additional steps are time consuming and may still result in a batch of paint having to be discarded or the vehicle having to be repainted.
A software-based system for color-matching relates a particular paint formulation to the VIN or vehicle identification number. While this system may minimizes some problems associated with manufacturing variability, it does not compensate for the natural aging of the paint on the vehicle or for mixing variation that may occur when the painter prepares only a small quantity of paint. The system does not provide guidance in color-matching a paint formulation once it has been mixed.
A spectrophotometric-based technique employs a software program in conjunction with a spectrophotometer. While such process will approximately match the hue of a painted substrate, they have difficulty accommodating the metallic or pearlescent appearance of some automotive paints. Goniophotometers or multi-angle spectrophotometers improve color matching results but are sophisticated and expensive pieces of equipment not ideally suited for collision repair facilities.
An additional aspect of color-matching is simulating the clearcoat that is very often applied over the base or color coat on modern vehicle paints. One method involves spraying the paint formulation onto one surface of a high gloss polyester film. The paint is then viewed through the polyester film with the film acting to simulate a clear coating. Although this method is effective for clearcoat simulation, it does not offer the painter guidance on adjusting the color of the paint in order to more accurately match the color of the target substrate.
In view of the foregoing, a need exists for an inexpensive, easy-to-use article to guide the painter in color-matching of a paint formulation to a target substrate, for example, a vehicle under repair.